Valve for internal-combustion engines.



`unirsi) srafras PATENT clarion.:

LODEWYK JAN RUTGER HOLST, OF LANSDOWNE, PENNSYLVANIA, ASSIGNOR OF ONE- THIRD TO MORRIS EARLE AND ONE-THIRD T0 HENRY S. WILLIAMS, BOTH'OF PHIL- ADELPHIA, PENNSYLVANIA.

VALVE FOR INTERNAL-COMBUSTIQN ENGINES.

Application led March 6, 1912. Serial No. 681,929.

To all 'whom t may concern.'

Be it known that I, LODEWYK JAN RUTGER HoLs'r,'a citizen of the United States, residing at Lansdowne. in the county of Delaware and State of Pennsylvania, have invented certain new and useful Improvements in Valves for Internal-Combustion Engines, .of which the following is a specilication.

The principal object of my present invention is to provide internal combustion engines working with the four stroke cycle with improved means for vhe prompt'alilux of the products of com\ .tion immediately after they have performed' their useful work so that only a minimum will remain in the cylinder to give off heat to the walls thereof, during the upward 4exhaust stroke, thereby also reducing the back pressure and thus generally improving the eliiciency 4of the en- A gine. This result is obtained by roviding the cylinder near its open end wit an auxiliary exhaust-port, which isuncovered by t-he piston as soon as it reaches on the downward stroke that point of its course at which the exhaust is to begin. As, however, this point is reached and passed also during the suction stroke means are provided to main- Ytain this auxiliary-port closed during the suction period or during that partof it, Where the piston uncovers said auxiliaryport.

I am aware that it has been proposed to f provide exhaust-ports near the open end Acycle principle, in which case no further of cylinders in engines working on the twoprotection for this port is required owing to the fact that each time the piston uncovers this port in such engines, that port is intended to lead ott the combustion products. In such instances this port is to be considered the principal exhaust-port. I am also aware that it has been proposed to pro- .vide engines working with the four stroke cycle but in which the suction and explosion strokes are of unequal length with an auxiliary exhaust port; and also in such engines no protection is required for this port as in "such cases the auxiliary-port is only uncoveredby the piston each time this port is intended to operate. [hxagm further aware that it has been proposed to provide engines working with the four stroke cycle witheily Specification of Letters Patent.

Patented Feb. 4, 1913.

haust-ports located at or near the open end of the cylinder and to use such ports as the only exhaust-ports,V eliminating the valved exhaust ports iu t-he combustion chamber, and such ports are thus far left unprotected during the suction stroke entailing a partialy loss of the charge, or are intentionally opened again by the action of automatically operating valves for the purpose of drawing in an additional charge of air at the. end of the suction stroke; also in many cases such ports are used for the admission of a scav.- enging or a cooling charge but do not act as exhaust-ports. None of these constructions, however, satisfy the purpose of my invention, which is to provide an auxiliary eX- haust-port. in combination wit-h positive closing means for the same duningtthe suction period, in order to dispose as promptly as possibi@ of um buik of the hear. Stord in the. exhaust gases, thereby reducing to a minimum the heating of the cylinder walls, and at the same time materially reducing the resistance of puppet-exhaust valves against opening the same, by previously receiving the excess pressure therefrom, as applied to engines with stationary cylinders in which the pistons reciprocate through equal strokes in all phases of a four cycle engine. n

I am still further aware that it has been proposed to operate auxiliary exhaust valves by means of separate cams attached to the half-time shaft.

The nature, scope and characteristic features of my present invention will be more fully understood from thejollowing description taken in connection with the accompanying drawing forming part hereof, which shows a vertical Cross-section through the central line of the cylinder of an engine in an adaptation of the same to an ordinary puppet valve construction.

Referring to the drawing, the cylinder 5,"

is provided with tne usual exhaust and suc-y the same side ot the cylinder', all of which immaterial for the purposes of this ,invention. Near the lower or open end, the cylgnder is provided with a port 6, communicating with a valve chamber l0, containing the auxiliary-puppet-valve 9. This valve 1s operated by means of the bell-crank lever 1Q, which is adapted to contact with the exhaustcam 11,:1suitabletime aheadof thecontact of such cam-with the valve-lift 13,0perating the principal exhaust-valve 7. By this arrangemont', the port 6, Will give exhaust to the combustion products the instant the piston uncovers the said port 6, and as the auxiliary valve 9, is lifted before this takes place, no pressure except that of the valve spring;r

14, need be' overcome, for the operation of the valve 9. During the period absorbed by ,theypiston t0 reach the lower limit on its fcontinued downward stroke and to again cover the outlet-6, in the upward exhauststroke, the main exhaust-valve is opehed by the cam 11, and valve-rod 13, thereby also reducing the effort required to lift the main exhaust-valve 7 t/o pr'acticallynot more than overcomin the spring pressure exerted on this'valve y the valve-springl. It will be evident that on the'suct-ion stroke the auxiliary-valve- 9 is closed, and thus prevents drawing in exhaust gases from the exhaustpipe when the piston overrui'is the port 6.

Having thusy described thenature and 0bjects of my invention, what I claim as new and desire to secure by Letters Patent is In an internal combustion engine having a. stationary cylinder provided with an eX- plosion-chamber, a main exhaust-valve communicating with said chamber, a cam operating said valve, an auxiliary exhaust-valve arranged near the open end of said cylinder and a lever interposed between said cani and auxiliary exhaust-valve to thereby open said auxiliary exhaust-valve in advance of'said main exhaust-valve, substantially as and for the purpose described.

In witness whereof, I have hereunto set my signature in the presence of the two subscribing witnesses her'eto. i

LODEWYK JAN RUTGER HOLST. lWitnessest J. WALTER DoUGLAss, THOMAS M. SMITH. 

